Macroporous Gel with a Permeable Reaction Platform for Catalytic Flow Synthesis.

We mimic a living system wherein target molecules permeate through capillary and cells for chemical transformation. A monolithic porous gel (MPG) was easily prepared by copolymerization of gel matrix, tertiary amine, and cross-linking monomer in one-step synthesis. Interconnected capillaries existed in the MPG, enabling flow application with high permeability. Because the capillaries were constituted of polymer gel, Pd(0)-loaded MPG provided another permeable pathway to substrates in a gel network, contributing to its much high turnover number after 30 days of use, compared with that of Pd(0)-loaded inorganic supports. Interestingly, the gel network size of the MPG influenced the catalytic frequency. Diffusivities of the substrates and product in the gel networks increased with increasing network sizes in relation to catalytic activities. The MPG strategy provides a universal reactor design in conjunction with a practical process and precisely controlled reaction platform.